Twitter Application Development For Dummies doc

™ Open the book and find: • Basics on using HTML, CSS, PHP, and MySQL • How to create and manage your developer account • Advice on choosing an idea for your app • An overview of Web ap

$response = $twitter->status->update ('Developing a killer new Twitter app!');

Dusty Reagan, @DustyReagan

Creator of FriendOrFollow.com Twitter app

Learn to:

success

Application Development

Making Everythi ng Easier!

™

Open the book and find:

• Basics on using HTML, CSS, PHP, and MySQL

• How to create and manage your developer account

• Advice on choosing an idea for your app

• An overview of Web apps, Twitter bots, mobile clients, and more

• Twitter’s two APIs

• Different ways to monetize your app

• Example code for every API method

• Code for a complete app

Dusty Reagan launched a Web development company called

Floating Head Studios in 2007 He developed the hugely popular

Twitter app FriendOrFollow.com in 2008, and a few months later

launched FeaturedUsers.com, a niche ad network centered around

the Twitter ecosystem Follow him on Twitter at @DustyReagan

$29.99 US / $35.99 CN / £21.99 UK

ISBN 978-0-470-56862-0

for videos, step-by-step examples,

how-to articles, or to shop!

Discover the fun of

building a Twitter app,

and earn some cash too!

Love Twitter? Know a little (or a lot) about developing

applications? Learn how to build a Twitter app, some great

ways to make it stand out from the crowd, how to get it

discovered, and how to turn your Twitter app-building

into a productive little business — all from the creator

of FriendOrFollow.com, one of the coolest Twitter apps

around!

• If your skills are rusty — check Chapter 2 for a quickie refresher

course in Web application development

• Exploring the ecosystem — explore the types of Twitter apps

already available and the five categories of the Twitter

ecosystem

• The money thing — learn about Twitter’s unusual financial

environment and ways you can earn money from your apps

• Build a Twitter Web app from the ground up — work with Twitter

API libraries, choose a Web hosting provider, and set up a Web

framework

• Get the word out — discover ways to promote your apps and

how to make your app business grow

Start with FREE Cheat Sheets

Cheat Sheets include

• Checklists

• Charts

• Common Instructions

• And Other Good Stuff!

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To access the Cheat Sheet created specifically for this book, go to

www.dummies.com/cheatsheet/twitterappdev

by Dusty Reagan

Application Development

FOR

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Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana

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10 9 8 7 6 5 4 3 2 1

2008, and a few months later launched FeaturedUsers, a niche ad network for the Twitter ecosystem.

Follow Dusty on Twitter at @dustyreagan

Author’s Acknowledgments

This book would not have been possible without the patience, love, and encouragement of my wonderful wife, Sharlee She was beside me through the whole journey, proofreading every word, acting as my sounding board, and being my emotional rock during those tight deadlines Thank you Shar I love you!

To all of my friends and family who put up with my social absence during the writing of this book, thank you for your encouragement and for enthusi-astically accepting me back into your lives when I crawled out of my writing cave, back into the daylight

Thanks to Chris Treadaway for introducing me to Katie Feltman Katie, you are a wonderful project editor and writer’s therapist Thank you for guiding

me through this wonderful experience

Pat O’Brien, thank you for your professionalism and editing expertise

Somehow you and Debbye Butler managed to make even my writing able

publish-Thank you Jaisen Mathai (@jmathai) and Abraham Williams (@abraham) for your technical help with OAuth You are both masters of your trade and exceptionally generous with your knowledge Follow them on Twitter and pay attention to what they have to say about Twitter API happenings

Thank you for reading I hope this book brings value to your endeavors

other comments, please contact our Customer Care Department within the U.S at 877-762-2974,

out-side the U.S at 317-572-3993, or fax 317-572-4002.

Some of the people who helped bring this book to market include the following:

Acquisitions, Editorial, and Media

Development

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Editorial Manager: Kevin Kirschner

Media Development Project Manager:

Laura Moss-Hollister

Media Development Assistant Project

Manager: Jenny Swisher Media Development Associate Producers:

Josh Frank, Marilyn Hummel, Douglas Kuhn, and Shawn Patrick

Editorial Assistant: Amanda Graham

Sr Editorial Assistant: Cherie Case

Cartoons: Rich Tennant

Publishing and Editorial for Technology Dummies

Richard Swadley, Vice President and Executive Group Publisher Andy Cummings, Vice President and Publisher

Mary Bednarek, Executive Acquisitions Director Mary C Corder, Editorial Director

Publishing for Consumer Dummies

Diane Graves Steele, Vice President and Publisher

Composition Services

Debbie Stailey, Director of Composition Services

Introduction 1

Part I: Catching Up to Twitter and App Development 5

Chapter 1: Catching Twitter’s Coat Tails 7

Chapter 2: Web Development Refresher Course 13

Chapter 3: Setting Up to Create Twitter Apps 39

Part II: Ideation — Coming Up with an Idea 45

Chapter 4: Getting to Know the Twitter Application Ecosystem 47

Chapter 5: Introducing the Twitter API 63

Chapter 6 : Logging In and Managing Your Account 79

Chapter 7: Managing Users and Their Relationships 105

Chapter 8: Communication Through Tweets 179

Chapter 9: Selecting an Idea 241

Part III: Creation — Developing Your Application 249

Chapter 10: Selecting Libraries, Design Patterns, and Frameworks 251

Chapter 11: Hosting In the Clouds 255

Chapter 12: Coding Your Application 269

Chapter 13: Making It Pretty Makes It Credible 309

Chapter 14: What You Need to Know to Grow 315

Part IV: Monetization — Making Money with Your Application 321

Chapter 15: How Twitter Makes Money 323

Chapter 16: Advertising 327

Chapter 17: Monetizing with Other Models 335

Chapter 18: Promoting Your Application 345

Part V: The Part of Tens 355

Chapter 19 : Ten Traits of a Respectable Twitter Developer 357

Chapter 20: Ten Twitter API Tips 361

Appendix B: Gallery of Twitter Applications 395 Index 413

Introduction 1

About This Book 1

What You Don’t Need to Read 2

Foolish Assumptions 2

How This Book Is Organized 2

Part I: Catching Up to Twitter and App Development 2

Part II: Ideation — Coming Up with an Idea 3

Part III: Creation — Developing Your Application 3

Part IV: Monetization — Making Money with Your Application 3

Part V: The Part of Tens 3

Icons Used in This Book 3

Where to Go from Here 4

Part I: Catching Up to Twitter and App Development 5

Chapter 1: Catching Twitter’s Coat Tails 7

Why Do People Tweet? 7

What Makes Twitter So Special? 8

Asymmetrical relationships 9

Follow and update using SMS 10

Trends and search 10

The open API 11

Why Should You Develop a Twitter App? 11

Turning Motivation into Action 12

Chapter 2: Web Development Refresher Course 13

Writing HTML & CSS 13

HTML Elements 16

Styling Your HTML 18

Formatting in XML & JSON 24

The Basics of PHP 25

Conditional Statements 26

Loops 28

Functions 29

Arrays 30

cURL 31

PHP DOMDocument Class 33

PHP json_decode Function 35

Understanding MySQL 35

Chapter 3: Setting Up to Create Twitter Apps .39

Create Your Developer Account 39

The Importance of Version Control 40

Hello Twitter! 41

Part II: Ideation — Coming Up with an Idea 45

Chapter 4: Getting to Know the Twitter Application Ecosystem .47

Desktop Client 47

TweetDeck 48

Seesmic Desktop 48

Twitterrifi c 49

Mobile Clients 49

Tweetie 49

TweetDeck 50

Tiny Twitter 50

Web Applications 50

Customer relationship management (CRM) 51

Contact management 52

Statistics 53

Media Sharing 54

Information aggregation 55

Information publishing 57

Advertising 58

Twitter Bots 59

Twittercal (@gcal) 59

Remember The Milk (@rtm) 60

Tweetname (@tweetname) 60

Hardware 60

BakerTweet 61

Botanicalls Kit 61

Tweet-a-Watt 61

Chapter 5: Introducing the Twitter API .63

Play Nice and Follow the Terms of Service 63

General Twitter Rules 64

Developer Etiquette 65

There Are Actually Two APIs 65

Twitter API Versioning 66

Rate Limits and How to Get White Listed 67

REST API Rate Limit 67

Search API Rate Limit 68

Getting Blacklisted 69

Defi ning the Payload 71

The User Object 71

The Status Object 72

Authentication 73

Chapter 6: Logging In and Managing Your Account 79

Account Methods 79

Verify a user’s credentials 80

Check your rate limit 81

End a user’s session 83

Updating a user’s notifi cation device 85

Update a user’s profi le 86

Update a user’s profi le colors 89

Update a user’s profi le picture 91

Update a user’s background image 93

OAuth Methods 95

Log a user in with OAuth 95

Get an OAuth request token 96

Get an OAuth access token 99

Chapter 7: Managing Users and Their Relationships 105

User Methods 105

Get the details of a user 106

Get user details of your friends and followers 109

Social Graph Methods 112

Get the user IDs of your friends and followers 112

List Methods 115

Create a new list 116

Update an existing list 118

Get a user’s lists 120

Get details on a specifi c list 122

Delete a list 124

Get a list’s timeline 126

Get the lists a user belongs to 129

Get the lists a user follows 132

List Members Methods 134

Get a list’s members 134

Add a member to a list 136

Remove a list member 138

Test if user is a list member 140

List Subscribers Methods 142

Get a list’s subscribers 143

Follow a list 145

Stop following a list 147

Test if user follows a list 149

Friendship Methods 151

Follow a user 152

Stop following a user 154

Check if one user follows another user 156

Get information about the relationship between two users 158

Notifi cation Methods 161

Follow a user to your phone 161

Stop receiving notifi cations 163

Block Methods 165

Block a user 166

Unblock a user 168

Check if a user is blocked 170

Get a user details list of blocked users 172

Retrieve a list of blocked users IDs 174

Spam Reporting Method 176

How to report a Twitter account as spam 176

Chapter 8: Communication Through Tweets 179

Status Methods 179

Get the details of a specifi c tweet 180

Create a new tweet 182

Delete a tweet 184

Retweet a tweet 186

Retrieve retweets of a particular tweet 188

Direct Messages Methods 190

Retrieve direct messages 191

Send a direct message 194

Delete a received direct message 196

Timeline Methods 198

Get tweets from the public timeline 199

Get your aggregated friends timeline 201

Get a user’s tweets 203

Get tweets that mention your screen name 207

Get status updates retweeted by you 210

Get your friend’s retweets 212

Get the retweets of a specifi c tweet 215

Favorite Methods 217

Retrieve a user’s favorite tweets 217

Add a tweet to your favorites 220

Remove a tweet from your favorites 222

Saved Searches Methods 224

Retrieve all your saved searches 225

Get the details of a saved search 227

Create a saved search 229

Remove a saved search 231

Search API Methods 233

How to search for tweets with the API 233

Get the current trending topics 235

Get the weeks trending topics 239

Chapter 9: Selecting an Idea 241

Imagining a Successful Twitter App 241

What Is Your Motivation? 242

Enjoyment 242

Make money 242

Filling a need 243

Make it better 243

Build your brand’s reputation 244

Support a cause 244

Why Do People Use a Twitter App? 244

Solves a problem 245

It’s entertaining 245

It’s easy to use 245

They trust it 246

Do You Have the Skill and Resources to Build Your App? 246

Enough Jibber Jabber! Start Building! 247

Part III: Developing Your Application 249

Chapter 10: Selecting Libraries, Design Patterns, and Frameworks 251

Twitter API Libraries Can Speed Up Development 251

Web Application Frameworks 252

Model View Control 253

Chapter 11: Hosting in the Clouds 255

Types of Web Hosting Solutions 255

Shared web hosting 255

Dedicated web hosting 256

Cloud computing 256

Choosing a Hosting Provider 257

Setting Up Your Servers 258

Setting up Apache and PHP 258

Setting up your MySQL server 263

Uploading Files to Your Web Server 266

Setting Up Your Domain Name 267

Chapter 12: Coding Your Application 269

Setting Up the Zend Framework 269

Create your project’s initial directories 270

Install the Zend Framework 271

Bootstrapping your application 272

Create your htaccess fi le 273

Create your index.php fi le 273

Create your bootstrap fi le 275

Create your confi g fi le 276

Create your layout template 277

Create your fi rst view and controller 278

Setting Up Your Data Structure 280

Build the User table 280

Build the Tweet table 282

Create Your Data Models 283

Defi ne your tables 283

Create the Tweet model 284

Create the User model 286

The Cron Jobs 295

1 Creating your auto-follow script 295

2 Creating your Tweet monitor script 301

Schedule your Cron jobs 303

Creating the Scoreboard 303

Update your IndexController 303

Add your pagination template 305

Update your Index view 306

Release Early and Often 307

Chapter 13: Making It Pretty Makes It Credible 309

Hire a Designer 309

PSD to XHTML 310

Integrating Your Design 311

Chapter 14: What You Need to Know to Grow 315

Automating Acceptance Testing 315

Unit Testing 317

Continuous Integration 317

Performance Concerns 318

Part IV: Monetization — Making Money with Your Application 321

Chapter 15: How Twitter Makes Money 323

Understanding Venture Capital 323

How to Fund Your Application 325

Self-funding 325

Outside investors 326

Selecting a Traditional Ad Network 327

Pay Per Click (PPC) 328

Cost Per Thousand (CPM) 329

Pay Per Action (PPA) 330

Cost Per Time (CPT) 331

Going Vertical 332

The Magpie Network 332

The Featured Users Network 332

Do It Yourself 333

Chapter 17: Monetizing with Other Models .335

Requesting Payment for Service 335

Ask for donations 336

Sell your software 337

Sell subscriptions 338

Selling Goods 339

Physical goods 340

Virtual goods 341

Building Your Business 342

Brand awareness 342

Be acquired 343

Chapter 18: Promoting Your Application 345

Social Networking 346

Twitter strategy 346

Facebook strategy 347

Web site blog 348

Opt-in e-mail list 349

Go Viral 349

Public Relations Strategies 351

Network in your industry 351

Toot your own horn 351

Be authentic 352

Advertise 352

SEO 353

Part V: The Part of Tens 355

Chapter 19: Ten Traits of a Respectable Twitter Developer 357

Ask Permission 357

Read the Documentation First 358

Stay Within Your Rate Limit 358

Don’t Promote Mass Following 358

Be Cautious of Trademarks 359

Give Back 359

Cache Your Data 359

Use OAuth 359

Don’t Be Evil 360

Communicate with Your Users 360

Chapter 20: Ten Twitter API Tips .361

Develop Defensively 361

Degrade Gracefully 361

Don’t Rely on screen_name 362

Use 64-Bit Integers 362

Subscribe to the Google Group 362

Access the API in the Background 362

Use JSON 363

Optimize Caching 363

Support International Characters 363

Do It Client Side 363

Appendix A: Twitter API Reference 365

Account Methods 365

account/verify_credentials 365

account/rate_limit_status 366

account/end_session 366

account/update_delivery_device 366

account/update_profi le_colors 366

account/update_profi le_image 367

account/update_profi le_background_image 367

account/update_profi le 368

Block Methods 368

blocks/blocking 369

blocks/blocking/ids 369

blocks/create 369

blocks/destroy 370

blocks/exists 370

Direct Message Methods 371

direct_messages 371

direct_messages/sent 372

direct_messages/new 372

direct_messages/destroy 373

favorites 373

favorites/create 374

favorites/destroy 374

Social Graph Methods 375

followers/ids 375

friends/ids 375

Friendship Methods 376

friendships/create 376

friendships/destroy 376

friendships/exists 377

friendships/show 377

Help Methods 378

help/test 378

Notifi cation Methods 378

notifi cations/follow 379

notifi cations/leave 379

OAuth Methods 379

oauth/access_token 380

oath/authenticate 380

oauth/authorize 380

oauth/request_token 380

Saved Searches Methods 380

saved_searches 381

saved_searches/create 381

saved_searches/destroy 381

saved_searches/show 382

Search Methods 382

search 382

trends 383

trends/daily 383

trends/current 384

trends/weekly 384

Spam Reporting Methods 384

report_spam 385

Status Methods 385

statuses/destroy 386

statuses/followers 386

statuses/friends 387

statuses/friends_timeline 388

statuses/home_timeline 389

statuses/mentions 389

statuses/public_timeline 390

statuses/retweet 390

statuses/retweeted_by_me 390

statuses/retweeted_of_me 390

statuses/retweeted_to_me 391

statuses/retweets 392

statuses/show 392

statuses/update 392

statuses/user_timeline 393

User Methods 394

users/show 394

Appendix B: Gallery of Twitter Applications 395

Index 413

Welcome to the first edition of Twitter Application Development For

Dummies, the book written especially for people who want to create

Twitter applications but haven’t a clue about how to start

About This Book

There are a couple of ways to use this book, depending on your preferences and experience

If you’re a Twitter newbie, you can start reading and working with Chapter 1 and keep going until you reach the index at the end Everything falls in sequence as you build experience and knowledge

This book also works like a reference Start with the topic you want to find out about Look for it in the table of contents or in the index to get going

The table of contents is detailed enough that you should be able to find most

of the topics you’re looking for If not, turn to the index, where you can find even more detail

After you find your topic in the table of contents or the index, turn to the area of interest and read as much as you need or want Then close the book and get on with it

Of course, this book is loaded with information, so if you want to take a brief excursion into your topic, you’re more than welcome If you want to know the ins and outs of building an online store, read the whole chapter on store-fronts If you just want to know how to post a product on your site, read just the section on adding products You get the idea

This book rarely directs you elsewhere for information — just about everything that you need to know about is right here If you find the need for additional

information on related topics, plenty of other For Dummies books can help

What You Don’t Need to Read

Aside from the topics you can use right away, some of this book is skippable

I carefully placed extra-technical information in self-contained sidebars and clearly marked them so that you can steer clear of them Don’t read this stuff unless you’re really into technical explanations and want to know a little of what’s going on behind the scenes Don’t worry; my feelings won’t be hurt if you don’t read every word

Foolish Assumptions

I’m making only one assumption about who you are: You’re a computer user

How This Book Is Organized

Inside this book, you find chapters arranged in five parts Each chapter breaks down into sections that cover various aspects of the chapter’s main subject

The chapters are in a logical sequence, so reading them in order (if you want to read the whole thing) makes sense But the book is modular enough that you can pick it up and start reading at any point

Here’s the lowdown on what’s in each of the five parts

Part I: Catching Up to Twitter and App Development

The chapters in this part present a layperson’s introduction to what Twitter development is all about

The best thing about this part is that it starts at the very beginning and doesn’t assume you know how to download and upload and extract and install software

It also suggests simple solutions on how to get started In other words, this part is aimed at ordinary people who know almost nothing

Part II: Ideation — Coming Up with an Idea

The goal of the chapters in this section is to get you started working on a great Twitter application There are technical details, and blue-sky tips

Part III: Creation — Developing Your Application

The chapters in this part show you how to take control of your application and detail it

Part IV: Monetization — Making Money with Your Application

Hey, there’s more to life than money That’s why we keep the money stuff safely tucked away here

Part V: The Part of Tens

This wouldn’t be a For Dummies book without a collection of lists of

interest-ing snippets

Icons Used in This Book

Those nifty little pictures in the margin aren’t there just to pretty up the place They have practical functions:

Hold it — technical details lurk just around the corner Read on only if you have a pocket protector

Pay special attention to this icon; it lets you know that some particularly useful tidbit is at hand — perhaps a shortcut or a little-used command that pays off big

Did I tell you about the memory course I took?

Danger, Will Robinson! This icon highlights information that may help you avert disaster

Where to Go from Here

Yes, you can get there from here With this book in hand, you’re ready to build your own robust and useful Twitter application Browse through the table

of contents and decide where you want to start Be bold! Be courageous! Be adventurous! Above all, have fun!

Catching Up to Twitter and App Development

The chapters in this part present a layperson’s duction to what Twitter development is all about

intro-Catching Twitter’s Coat Tails

In This Chapter

▶ Why Twitter is a compelling platform

▶ The rationale behind building a Twitter app

A few years ago a small Web site called Twitter appeared on the Internet

Twitter is kind of like a blog, but your posts must be less than 140

char-acters Twitter users call their posts tweets Of course, your tweets have to

be that small to be sent as a text message to your followers That’s Twitter lingo for subscribers to your Twitter updates, usually your friends, family, and fans As it turns out, my dad is one of my biggest fans All of my small daily updates about my life go straight to his cell phone Likewise, all of his updates go to my phone This way we get to share little things we wouldn’t otherwise take the time to call and talk about This helps bring us closer together, even though we live miles apart

The idea of keeping in touch with friends and family is comforting and increases Twitter’s appeal, but Twitter has even larger implications

Why Do People Tweet?

You already know one reason I tweet, to stay close to friends and family

But there are several other reasons why people might be compelled to get involved with Twitter Here are a few examples:

✓ Stay in touch with friends and family

✓ Get instant advice from friends

✓ Keep informed of stock market trends

✓ Build cool stuff with their open API

✓ Build a business around Twitter

✓ Promote a business with Twitter and interact with customers.

✓ Get involved in politics

✓ Stay informed of breaking current events as they happen

✓ Talk to influential people and celebrities

These are just a few common reasons why someone might be on Twitter

There are even more creative uses of Twitter In Chapter 4, you learn about

a plant that tweets when it needs to be watered You can also use Twitter to update your Google Calendar by sending a direct message to @gcal If you want to know the time in London, you can follow @big_ben_clock that bongs every hour on the hour

Perhaps a more practical example of creative Twitter use is @AusTraffic, run

by the Austin American Statesmen newspaper The account includes only

tweets on traffic conditions in Austin, Texas People can even direct message (DM) the account to send traffic reports, which are then shared with all the account’s followers If you follow this account to your phone, you have an instant, real-time feed of traffic conditions in Austin

One of Twitter’s strengths is that it doesn’t limit what people can do with it

Nor do they presume to know exactly how everyone should interact with it

The founders of Twitter have left it up to the users to discover what Twitter

is to be used for and how

Some now common features of Twitter were originally derived out of how the Twitter community decided to use the application @ replies for instance were invented and adopted by the Twitter community first @ replies are used when one Twitter user references another Twitter user’s screen name For example,

if someone wanted to mention me in a tweet, they would type @DustyReagan

Twitter noticed how people were using the @ sign when they referred to another Twitter account, and to make the @ sign more helpful, Twitter linked

it to the referred users account Then they made it so you could search for all mentions of your screen name Some other conventions that came out of the

Twitter community include hashtags and retweets

What Makes Twitter So Special?

Twitter’s premise is simple, but its effects are wide-reaching Here are four features of Twitter that make it more than a blog with 140 character posts:

✓ Asymmetrical relationships

✓ Follow and update using SMS

Asymmetrical relationships

Twitter’s relationships structure is simple, but revolutionary Before Twitter, most social networking sites, such as Facebook (http://facebook.com) and MySpace (http://myspace.com), required mutual friendships You couldn’t see a user’s information if he or she didn’t specify you as a friend

Twitter threw this model out the window

On Twitter, you can follow the updates of anyone who has a public account, and they don’t have to follow you back This means celebrities and politicians can communicate with their fans and constituents without becoming friends with half of the Internet’s population This asymmetrical relationship model parallels relationships in real life There are people whom I admire, who have simply never met me Now I have a way to stalk those people! I can even send their updates to my phone I write this with tongue in cheek — well, the stalking part anyway Unless your account is private, tweets are intended to be public broadcasts of information

A brief glossary of terms

If you haven’t been around the Twitter block, you need to learn a few Twitter-specific terms

to communicate with your new Twitter friends and colleagues

✓ direct message — Sometimes referred to

as a DM, a direct message is a private sage sent to you, or by you, over Twitter

✓ FailWhale — In the early days of Twitter, the small company suffered from growing pains as its application became popular

Unfortunately, this caused Twitter to crash frequently When Twitter was down, an illustration of several birds lifting a whale out of the sea via ropes held from their beaks was displayed This image became

known as the FailWhale.

✓ hashtag — A word proceeded with a # sign

Hashtags are used to signify that a status update is about a particular topic to allow for easy searching For example, confer-ence goers may tag all of their updates with a hashtag unique to the conference so

other attendees can read all the updates pertaining to the event

✓ @ replies — Pronounced “at replies.”

@ replies are how you reference another Twitter user For example, I am @DustyReagan You use @ replies to direct a tweet

to a user or to mention a user in passing

@ replies are sometimes referred to as

“mentions” or a “mention.”

✓ retweet — Abbreviated RT A retweet is

a status update from someone you follow that you share with your followers, by using Twitter’s built-in retweet feature or by copy-ing the update attributing the original author and posting it from your Twitter account

✓ tweet — A tweet is another word for a status update It can be used as a noun or a verb For example, you can tweet a tweet

✓ twoosh — A tweet that is exactly 140 characters

Follow and update using SMS

I usually attend one or two technical conferences per year These conferences usually last a few days, and I may know a few people at the event Attending the panels is straightforward enough, but there is valuable time in-between panels and after the conference when people meet up, have a good time, exchange ideas, and so on At these times, you have two options: find out where every-one is hanging out and join them, or go back to the hotel

Twitter is my lifeline during these times At conferences, I follow the people I know using SMS updates that are sent to my phone This way, I know where the good parties are, where the free beer is, and where the conference pre-senters are hanging out

Still not convinced about the usefulness of SMS updates? Here’s another example

Many news organizations have seen the potential of broadcasting news to Twitter If you want to stay up-to-date on current events, you can’t get much more current than having headlines sent to your phone in near real-time

Along with receiving updates to your mobile phone, you can post updates to Twitter using SMS This feature allows users to update their Twitter status while they’re on the go, in real-time The next time you go downtown for drinks or head to the coffee shop for a mid-afternoon cup of espresso, you can alert your friends This may cause an impromptu gathering of good friends

Trends and search

Following the Twitter accounts of news organizations to stay on top of current events is one option, but using Twitter, you can get information on newsworthy events even before the news organizations do

One way to do this is by monitoring trending words and phrases on Twitter

Twitter has this functionality built in and provides the current trending topics

to all users When real-time events occur, they often spread organically by word of mouth, bubbling up in popularity until they become a trending topic

A frequently referenced Twitter news-breaking event happened on December 20,

2008, when Mike Wilson (@2drinksbehind) tweeted that he was just in a plane crash Thirty-eight people in the crash were injured Everyone survived

News of the event spread quickly on Twitter before any major media outlet could cover the event

for news on a particular subject, you can use Twitter’s search functionality

Using Twitter Search, you can monitor Twitter for words and phrases in near real-time You can even limit your results to tweets from particular geographical locations

Search is also useful for monitoring mentions of your company’s brand name or product You can then interact with users who are talking about your brand from your company’s Twitter account Never before has it been this easy for a brand

to contact customers about their concerns before their customers contact them

The open API

The real reason Twitter is so appealing to developers, inventors, hackers, and entrepreneurs is the open API Twitter provides all its data and functionality for free as an open API This means you can invent and build new applications around Twitter’s functionality You can even create a whole new Twitter inter-face from the ground up

Twitter encourages development with its API and has even acquired nies that build spectacular applications on top of Twitter Twitter’s current search engine was once an independent company called Summize

compa-The open API is probably the reason you picked up this book

Why Should You Develop a Twitter App?

Opportunities to build interesting and compelling things in and around Twitter abound Some third-party applications have started to show themselves as the leader in a particular facet of the Twitter ecosystem But these leaders could use some competition, and there are still opportunities to use Twitter

in ways no one has even thought of before Developers are constantly pushing the envelope on how Twitter can be useful and entertaining

I built my first Twitter app, Friend Or Follow (http://friendorfollow.com), because I wanted to know who wasn’t following me back on Twitter Plus

it was something fun to do on the weekend As it turned out, other people found Friend Or Follow useful as well As my app’s popularity began to grow,

I realized I could make money with it through advertising Suddenly I had a small business built on top of Twitter

If you’re looking for a reason to build a Twitter app, money could be one of them However, it can also be fun and rewarding to learn something new, and

if you’re fortunate enough to gain an audience with your app, it can be really gratifying to build something people appreciate

Here are few reasons why you might want to develop a Twitter app:

every day There are numerous ways to make money developing Twitter applications I cover this in detail in Part IV

people find useful or entertaining, you will gain a reputation with the users of your app

an app that raises awareness and money for a charitable cause or a philosophical idea See TwitCause (http://twitcause.com) for an example of this

✓ Fill a need: If there is something you don’t like about Twitter, you can fix it

using the API It’s quite likely several other people share your sentiments and will enjoy your fix

cause building a Twitter app, you can promote a brand with a Twitter app For example, @twelpforce is a Twitter account used by Best Buy They built an internal application that allows their employees to respond easily to technical inquiries directed to the account

can’t help it, and that’s awesome! Build something cool because it’s fun

Turning Motivation into Action

I hope you’re now motivated to start building a Twitter app Now it’s time to turn that motivation into action

The next chapter is a refresher course on Web application development using a LAMP (Linux, Apache, MySQL, and PHP) stack

If your Web development skills are strong, feel free to head straight to Chapter 3 where you post your first message to Twitter using the API

Web Development Refresher Course

In This Chapter

▶ The basics of Web development

▶ A look at the LAMP stack

▶ Reference material for the Web developer

An interesting thing about Twitter application development is you can

interact with the API in any language and on any platform Windows clients, iPhone applications, and Android apps use different programming languages and still interact with the Twitter API in similar ways

In this book, I use a typical LAMP (Linux, Apache, MySQL, and PHP) stack

to demonstrate the Twitter API I use the Web platform as a teaching tool because it has become prevalent, multiplatform, and Twitter itself is a Web app I use a LAMP stack because it is a widely adopted development platform and all the components are open source and free

If you’re already an expert LAMP user, you can skip to Chapter 3

If Web programming isn’t your native language, read this chapter However, this isn’t a definitive LAMP resource The topics in this chapter could easily fill several books on their own My aim here is to show you enough to get you through the rest of the book

Writing HTML & CSS

If you’ve done Web development work before, you’re probably familiar with HTML and CSS HTML (Hypertext Markup Language) is the language of the Web Web browsers interpret the semantics of the HTML elements, called tags, and render a human readable page for the visitor CSS (Cascading Style

Sheets) is the markup language that tells the browser how the HTML ments are to be styled and displayed In the early days of the Web, HTML often contained both the content of the Web page and information on how the page was to be styled Developers would often inappropriately use HTML tables to structure page elements, and the HTML specification included tags that defined display style such as “font” and “bold.” These tags have since been deprecated The modern practice is to separate content from style.

ele-There are several reasons to separate content from style

✓ Style changes are simple For example, using external CSS you can

change style elements site wide, like font size and background color

✓ HTML code is easier to read with the style elements removed This

makes maintenance easier

✓ File sizes are decreased, which increases the speed of your Web site

✓ Coding to Web standards increases the likelihood your site will render

correctly in a wide variety of Web browsers

✓ The order of your content can be structured logically like a document

because you can rearrange elements aesthetically using CSS This means

in cases where aesthetics are irrelevant, such as screen readers for the blind, and search engine spiders, your Web page will still be readable

The organization that writes the standards on HTML, CSS, XML, and ous other Internet protocols is the W3C (World Wide Web Consortium) This organization is made up of organizations that have a stake in Web standards

numer-Some obvious examples are companies that build Web browsers, such as Microsoft, Mozilla, and Apple Without the W3C there would be numerous proprietary versions of HTML and developers would be forced to develop to the most popular browsers

The W3C writes specification documents on how each version of HTML is to function With each new version of HTML comes a new specification docu-ment Web browsers are supposed to render your HTML based on the speci-

fication document, called a doctype, which you choose and declare in your

HTML So if you declare your page HTML 4.01, the browser should render your page based on HTML 4.01 rules Current doctypes include

XHTML (Extensible Hypertext Markup Language) is an HTML specification that is designed to make HTML more like a semantic collection of data, simi-lar to XML It relies on CSS to define the page’s design The key difference between HTML and XHTML is that XHTML must be valid XML The rules for HTML are much more lenient in this regard.

Here are some rules to make your HTML valid XHTML:

✓ The root element must be html and must contain an xmlns attribute that

defines the XHTML namespace

✓ You must always close XHTML tags including empty elements like the

break and image tag A closed break tag looks like this: <br />

✓ All XHTML tags must be lowercase

✓ All XHTML tag attributes must have a value You cannot shorten

an attribute such as readonly That attribute must appear as:

readonly=”readonly”

✓ All XHTML tag attributes must be surrounded by quotes

Here is an example of a short valid XHTML document:

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”

<p>Tags must be lowercase and closed,<br />

including singleton tags like the break tag.</p>

</body>

</html>

HTML Elements

HTML documents contain two main sections: the head and the body

The head occurs at the top of the file and is denoted by the <head> tag It contains non-visual information about the page, and usually contains these tags:

✓ title: Denotes the name of the Web page This usually appears at the

top of the browser window, and is used in bookmark labels and search engine results

✓ link: The link tag is used to link other resources to this Web page

Examples include external CSS files and favicons (the tiny 16 x 16 icon that is displayed in your bookmarks and browser address bar)

✓ meta: The meta tag is used to define ancillary information about a Webpage,

such as keywords, a short description, or copyright information

✓ style: Used to embed document wide CSS code directly in the head

By default, block-level elements occur on a new line Block-level elements may contain nested block-level tags and inline tags Examples include ✓ Headings: Heading tags are used to separate a document by topics and

to define the header row <th>, a row <tr>, and a column <td>.

✓ Forms: Forms are used to send user input data back to the hosting

server Forms are vital part of HTML and are necessary for nearly all ecommerce and Web applications, including Twitter While the form tag

is a block-level element, the field tags are inline elements

<form name=”input” action=”login.php” method=”post”>

Username: <input type=”text” name=”username” />

Password: <input type=”password” name=”password”>

<input type=”submit” value=”Submit” />

</form>

✓ DIVs: The div tag is a generic block-level element It is used primarily to

wrap sections of your document in logical blocks, so they can be easily manipulated and styled with CSS

✓ Anchor links: Anchor tags make the World Wide Web a Web Links to

external sites and internal pages weave a Web of information and nects the Web The anchor tag contains an important element called

con-“target” that tells the browser to open the link in a new or the current window By default the link will open in the current window You can specify target=”_blank” to have a link open in a new window

<a href=”http://twitter.com” target=”_blank”>Twitter</

a>

✓ Images: Image tags display images They contain several important

attri-butes including alt, title, height, and width The alt attribute is short for alternative text; it’s used to provide text description of the image The title attribute is the text that will appear in a browser tooltip when your cursor is hovering over the image Naturally the height and width attri-butes define the images height and width By defining an image’s height and width, the browser doesn’t have to wait for the image to finish download to correct render the elements around the image You can also use height and width to force an image’s size However, this doesn’t alter its file size

<img src=”http://twitter.com/logo.gif” alt=”Twitter

Logo” title=”Twitter” height=”100” width=”80”

/>

✓ Strong: The strong tag is used to denote a word or phrase as important

Its default behavior is to bold the word or phrase However, using CSS you may style the important text however you wish

Please do <strong>not</strong> delete these files

✓ Line break: Browsers ignore line breaks in HTML markup To tell the

browser you want a new line, you must use a <br /> tag

<p>The White House<br />

1600 Pennsylvania Avenue NW<br />

Washington, DC 20500</p>

Styling Your HTML

You can style HTML with CSS in three different ways:

✓ Inline: You can use the style attribute on any HTML tag to add style to

an element It looks like this:

page by placing your CSS in between the style tags, like this:

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”

✓ External File: The best option is to create an external CSS file with all

your styles in it and link to it from your HTML file, like this:

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”

If these three methods are applied to the same element at the same time, the inline CSS takes precedence over the embedded CSS, which takes precedence over the external CSS file.

When styling your CSS, you use selectors to specify what HTML attributes you want to style There are four main CSS selectors you should know for this book:

✓ Type selectors: Type selectors use the HTML tag name to identify what

tags you want to style For example, to give all the paragraphs on your Web site a margin of 10px, you would do this:

p { margin:10px;}

✓ Class selectors: You can add a class attribute to any HTML tag and

select elements with a particular class name using a dot followed by the class name For example, you might want to add a class called e-mail to all link tags that link to an e-mail address To select and style all those e-mail links, you would do this:

.email { color:red; }

✓ ID selectors: You can give any HTML element an ID attribute However,

the ID you give the element must be unique to the page You can’t have duplicate IDs on the same page To select an element based on its ID you use a pound sign like this:

#navigation { margin-top:20px; }

✓ Descendant selectors: You can select elements nested inside of other

elements by using a descendant selector For example, if you wanted

to select all the links inside of a div tag with and ID called “footer” you would do this:

#footer a { color:red; }

These are the primary CSS selectors you need to have a firm grasp on

When dealing with CSS selectors, you need to consider the nature of cascading style sheets Cascading styles work by applying the styles of the most general selector first, then overwriting those styles with more specific selectors The order of which the rules are encountered by the browser is irrelevant To give you an example, a general selector could be a style applied to all paragraphs like this:

p { margin:10px; color: red;}